It is conventionally known that tetrakisphenols and imidazole form a clathrate compound and it is also known that those exert their superior potentiality as a curing agent or a curing accelerator for epoxy resins.
For example, Patent Document 1 describes a curing agent for epoxy resins, characterized in that the agent consists of a clathrate of a tetrakisphenol-based compound and a compound that cures epoxy resin by reacting with epoxy group. TEP and 2P4MHZ are exemplified as a tetrakisphenol-based compound and a compound that cures epoxy resins by reacting with epoxy group, respectively.
Patent Document 2 describes that when TEP and 2P4MHZ are suspended in ethyl acetate, heated under reflux for 3 hours, and then cooled to room temperature, crystals of a clathrate compound can be obtained.
Further, Patent Document 3 describes a method of producing a clathrate compound, comprising preparing the compound by dispersing a solid host compound triturated in advance to an average particle diameter of less than or equal to 1.6 μm and a solid or liquid guest compound into a poor solvent of a solid host compound and a solid or liquid guest compound and keeping the temperature more than or equal to 50° C. and less than or equal to the release temperature of the guest compound, and water is exemplified as a poor solvent.